<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <script src="https://cdn.bootcss.com/jquery/3.4.1/jquery.js"></script>
  <title>代理解决跨域</title>
</head>

<body>
  <button onclick="doUpload()">提交</button>
</body>
<script>
  function doUpload(){
    $.get('http://localhost:3000/cors',{},(data)=>{
      console.log(data);
    })
  }
</script>
</html>